Two-piece jet thrust motor



Aug' 26 H. RUTlS-HAUSER vETAL I 2,426,526

'110 PIECE JBT THRUST IOIOR Filed .my 22, 1944 2 sheets-sneet'i v 2a 22 F151. 4 2 z 7 www Patented ug. 2,6, 194i s s UNITED 'STATES- PATEN'I" ori-ICE TWO-PIECE JET THRUST MOTOR Hans Rutishauser, Altadena, Robert C. Brumiield, i Arcadia, and Fritz Zwicky, Pasadena, Calif., assignors to Aeroiet Engineering Corporation, Azusa, Calif., a corporation of Delaware Y Application July 22, 1944, Serial No. 546,114

This invention relates to Jet thrust motors.; and particularly to jet motors utilizing -a propel.

laut adapted to lbe placed in the combustion chamber oi' the motor.

Jet propulsion motors have heretofore been usedin which solid propellant materials have` been placed or cast into the combustion chamlber and then ignited so that the gases of comiired. 'I'his difficulty has been largely due to,

the fact that the motor must be taken apart in some way, for the parts have tended to become corroded or stuck together after a combustion hasA taken place. 'I'he object of this invention is to provide a motor construction which permits easy lling and refilling of the motor chamber with combustible propellant. f

In accordance with our invention we provide a construction which readily permits the motor to be taken apart after a combustion for reloading. We have carried this outby building the motor in two parts to be attached together when the motor is loaded. A feature of the arrangement is the provision for holding one of the parts to the other, at least one of these holding devices being combustible so that after a combustion has occurred the attachable parts become loosened,`permitting easy detachment.

The foregoing and other features of the invention will be better understood from the following detailed description taken in commotion with the accompanying drawing in which:

Fig. 1 is an elevational View in part cross section along line I-I as shown in Fig. 2 of our invention;

. comprising a tubular chamber I having an open end provided with a slightly enlarged collar 2 and a closed end, preferably in the shapeKof a curved cap 3 which provides a base for the solid 8 Claims. (Cl. Bil-35.6)

`propellant cartridges I1. Collar 2 has a recess 5 provided with la tapered entrance portion 6. A combustible ring 4 is inserted in the recess 5 and is made of a combustible substance which I' is hard and tough and somewhat resilient soas to act as a strong washer. Materials useful for this purpose are cellulose nitrate, methyl methacrylate, etc. Adjacent the tapered portion 6 in recess a groove l is provided for receiving 10 two halves 8 and 9 of a ring or if desired a snap ring 25 as shown in Fig-4. The latter ring 25 orthe two halves 8v and 9 may be of suitable material such as cast iron or steel. An exhaust nozzle II, formed as a separate piece from the l5 chamber portion, has a ange I2 which may be `slightly undersized permitting easeI of insertion into the recess 5 of collar 2. 'I'he groove 22 is' provided in the iiange YI2 for receiving a resilient steel ring 23 which makes theA connection pressure tight. Steel ring 23 is gradually contracted 25 wardly forming an annular expanded portiony I4.

An electric ignitor I5 is installed in the upper portion of wall I6 of the exhaust nozzle for igniting the propellant charge I1 in the chamber I. A pressure relief device 20 isk secured in the lower portion of wall I6 in a conventional manner. The pressure relief device 20-contains a diaphragm I9 which may be ruptured when the pressure in the chamber I reaches a predetermined maximum. The surplus gases escape 20 thereby protecting the jet motor.

The propellants for this type of motor are frequently packed in the form of separate cartridges. and such loose cartridges are adapted to be o secured in the tubular chamber of the jet motor.

This isdone by the insertion of the above mentioned combustible ring 4 against the cartridgeI y or cartridges in the chamber of the motor. The /locking of the cartridges into the chamber is obtained by inserting Athe exhaust nozzle ilange I 2 intoethe recess 5 and driving it against ring 4. The whole assembly is then secured by the insertion of the two ring halves 8 and 9 which are held in place by the inserted screws I0.

The extreme end of the exhaust nozzle II is provided with threads 30. -The threads 30 serve to secure a pipe cap 3l which has a concentric threaded hole into which a water hose 32 'may be screwed. Two clips 33.may be provided in the '55 Wall I6 of the exhaust nozzle II. These clips :i3v

through the holes I8 in the pressure relief device may be part of the exhaust nozzle if the same is made of cast steel, or they may be welded if the exhaust nozzle is made of steel.

In operation the jet motor is fired by igniting the propellant charge I1. The electric ignitor I5 ignotes a small propellant charge (not shown) which injects a flame into the propellant charge Il, thereby igniting it. The ensuing combustion burns the combustible ring 4, but, while the combustion goes on the ilange I2 of the nozzle remains held against ring halves 8 and 9 by the pressure in the chamber. The combustion generates a large amount of products of combustion which escape through the exhaust nozzle II, producing the desired jet thrust. When-'the total charge is consumed flange I2 becomes loose within collar 2, since the ring 4 is now burned out. The motor can then readily be reloaded after it has cooled down sufficiently.

The reloading is performed by removing screws I and the two ring halves 8 and 9. In order to remove these halves the exhaust nozzle may be driven into the recess as the combustible ring 4 has been previously consumed. The space, which ring 4 has occupied serves as the space in to which the ange I2 of the exhaust nozzle may be driven, permitting easy removal of the two halves 8 and 9 of the retaining ring. During the operation of the motor a certain amount of residue from the vcombustion may have been deposited in the clearance between recess 5 and the ange I2.` This may prevent the easy removal of the exhaust nozzle. In order to speed up such removal the pipe cap 3I Fig. 1 may be screwed on the exhaust nozzle and water pressure is applied through hose 32 which pushes the nozzle out of the recess 5. Clips 33 serve to pull the nozzle out of the chamber if needed. After blowing out the dirt and ashes and some scrapings of the walls of the tubular chamber I, a fresh supply of propellant cartridges is placed in the chamber, and a fresh combustible ring 4 -is inserted into the recess 5 resting against the propellant cartridges. The cleaned exhaust nozzle ris inserted into the recess 5 and forced against ring 4 permitting the'insertion of the two halves 8 and 8 into the internal groove 6.

Screws III are screwed down locating the two halves 8 and 9. Themotor is now ready for the next operation. l

In Figs. 3 and 4 we show a construction which can be used alternatingly to that shown in Figs. 1 and 2. Figs. 3 and 4 show the same construction as in Figs. 1 and 2 except that instead of the retaining ring being of two halves 8 and Il it is a snap retaining ring 25. When using the snap ring 25 as a retaining ring the screws I0 are not needed. Such snap ring may be'of cast iron or resilient steel and may be contracted before permitting it to snap into the provided groove 6 in the recess 5 of collar 2 in the tubular chamber.

In Figs. 5 and 6 we show another modication of our invention. The steel ring 23 shown in Fig. 1 is eliminated. A slight taper of the exhaust nozzle flange I2 permits easy insertion into the recess 5 as shown in Fig. 5. 'Instead of the simple screws III a more elaborate construction is employed for securing the retaining ring halves 8 and 9. 'I'he outside face 40 of the collar 2 receives founclamps 4I for securing the two halves 8 and 9 in position. The four clamps 4| are tightened with the corresponding screws 42 into. the outside face 40 oi the collar 2.

After the firing of this embodiment is perthe recess 5 and the tapered ange I2 is filled with sediment. This sediment may be washed out with water before attempting to drive the exhaust nozzle flange I2 down into the space provided by the burning of the combustible ring 4 in the recess `5. Clamps 4I are removed by unscrewing the screws 42 prior to the removalrof the two ring halves 8 and 9.

It is understood that any of the above-described modications are operable in the same manner as described under-Figs. 1 and 2,

It is clear that we have provided a jet thrust motor which can be easily reloaded in the field or anywhere away from any assembling plant or the like.

We claim:

1. The combination in a jet propulsion motor having a combustion chamber member and an exhaust nozzle member for exhausting gases from said chamber, means for attaching and detaching the chamber member and the -nozzle member, said meanscomprising a flange on one member and a collar on the other member adapted to t within the ange, a pair of retaining rings held between said collar and flange, at least one of said rings being inflammable and adapted to be burned during the combustion within the chamber.

2. In a jet motor utilizing solid propellant material the combination comprising a combustion chamber having a closed end for supporting said propellant material and an open end provided with a recess, a combustible ring member for securing said propellant material in said chamber, an exhaust nozzle having a flange, said Ilange ttinginto said recess and against said combustible ring member, a retaining member inserted in said recess for securing said-exhaust nozzle in the chamber.

3. In a jet thrust motor the combination comprising a chamber for loading propellant material, said chamber having a closed end for supporting said propellant material and an open end provided with a recess, a combustible ring member in said recess for seeuring'said propellant material in the chamber, an exhaust nozzle having a flange, saidv ange fitting into sai'd recess and against said combustiblering member, a` retaining member inserted in said recess for securing said exhaust nozzle'in the chamber.

4. In ayjet thrust motor the combination comprising a tubular chamber for storing propellant cartridges, said tubular chamber having a closed end for supporting said cartridges and an open end provided with a recess, a combustible ring member in said recess, an exhaust nozzle inserted in said recess and having a flange pressing against said combustible ring member thereby securing said propellant cartridges in the tubular chamber and, a retaining member" for securing said exhaust nozzle in said tubular chamber.

lant cartridges, an internal groove provided in said recess for receiving a retaining member, said retaining member connecting said tubular chamber and the exhaust nozzle.

6. Ina jet thrust motorutilizing solid propellantv cartridges, the combination comprising a formed it has been found that the space between fuel chamber having a closed end for supporting sertion into said recess and against said combustible gasket, an internal groove in said recess for receiving a retaining member, said retaining member'connecting said fuel chamber and said exhaust nozzle.

7. In a jet thrust motor utilizing solid propel- Alant cartridges, the combination comprising a propellant chamber having a closed end for receiving said propellant cartridges, an open end in said chamber having a collar provided with a recess, -a combustible gasket inserted in said rezle, the burning ol' said combustible ring providing clearance for forcing said flange into it, thereby permitting easy removal of said retaining member.

8. In a jet thrust motor utilizing solid propellant cartridges, the combination comprising a fuel chamber having a closed end for containing the propellant cartridges, and an open end provided with a collar having a recess, an exhaust nozzle having a flange, a combustible gasket in the recess between the flange and the chamber, said flange having a groove and said collar having a corresponding groove, and a resilient ring member engaged in the grooves of the collar and ilange for retaining the flange in position against the combustible gasket.

- HANS RU'IISHAUSER.'

ROBERT C. BRUMFIELD. FRITZ ZWICKY. 

